


Just Because We Have To

by keep_waking_up



Category: Supernatural
Genre: Angst and Humor, M/M, Mildly Dubious Consent, Sibling Incest, They have to have sex to stop the apocalypse
Language: English
Status: Completed
Published: 2013-04-17
Updated: 2013-04-17
Packaged: 2017-12-08 19:13:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,213
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/765011
Author URL: https://archiveofourown.org/users/keep_waking_up/pseuds/keep_waking_up
Summary: <blockquote class="userstuff">
              <p>Of course, this would be the only way they could keep the angels off (or out of) their asses.  Speaking of asses, Dean really doesn’t want to think about asses at this moment in time.  Or things going in them.  Oh god.</p>
            </blockquote>





	Just Because We Have To

**Author's Note:**

> For spnkink_meme: There is one surefire way to keep from becoming an angel suit, and that is consistent, monogamous incest. Both Sam and Dean pretend they aren't into it while having monumental amounts of angst over how much they're enjoying getting it on with their brother. As weird as it is, it's nice knowing that they're actually getting closer than their abnormally close bond was before. Neither Sam nor Dean were into gay sex before, so they have to do a lot of experimenting to get things right. But they're both secretly turned on by making the other 'his.'

“Seriously?”

Of course, this would be the only way they could keep the angels off (or out of) their asses. 

Speaking of asses, Dean really doesn’t want to think about asses at this moment in time. Or things going in them. Oh god.

Bobby clears his throat, face a beat red as he squirms in his wheelchair. Bringer of the bad news, Castiel, of course just stands by serenely, although if Dean squints he can see him looking... a little concerned. And Sam’s gone just about as pale as he can get. He almost looks like he’s going to topple over like the giant redwood tree he is. Dean’s almost tempted to shout timber.

Calmly, Castiel nods like he didn’t just suggest- well, what he suggested. “Yes, seriously Dean. The one guaranteed way to keep Michael and Lucifer out of your bodies, even if you do say yes, is to have a consistent, monogamous, incestuous relationship. Normally, it is difficult for anyone to do this, seeing as most people aren’t privy to the reality of angels, and even if they are, they’re siblings are not. I have to say, we have an almost ideal situation here. A mutually beneficial relationship.”

“Ideal?” Dean croaks out, because it doesn’t look like Sam’s going to say anything. In fact, from the way he’s moving his mouth, he may have been turned into a fish. “Having to fuck my brother up the ass repeatedly-”

“And exclusively!”

“-and exclusively does not sound like any kind of ideal I’ve ever heard of!” He starts pacing as much as he can within Bobby’s study. With is basically three steps in either direction. He feels like a wind-up toy. Honestly, at this point, he’d pretty much prefer to be a wind-up toy. “Even if we’re not talking about the creepy incest thing, Sam and I aren’t gay, no matter how much he likes to act like it!” He glances in Sam’s direction to see if he’ll respond to the insult. Nope. “C’mon Cas, there’s got to be another way!”

Cas looks at him almost pityingly and that is just it. “I’m sorry Dean, but this is the only surefire way. I suggest you take a few hours to accustom yourselves and then start making arrangements.”

“Cas!” 

Of course, the feathery dick just decides to disappear after dropping that bombshell. Fucking coward. Dean sighs and leans back against the wall. “This is fuckin’ ridiculous. Like hell are we gonna do that.”

“What makes you think you’ve got any other choice, boy?” Bobby’s still about as red as he can get without his head exploding, but he seems to have recovered himself better than Sam. Who is... Dean’s not entirely sure what he seems to be doing now. Whatever. “Look, I like it just as little as you do. But it’s a hell of a lot better than both of you becoming meatsuits to a couple of angels that possibly have more daddy issues than you do!”

Seriously? “You can’t be buying into this shit Bobby! I mean, really, magical incest sex is gonna stop a couple of feathered freaks from hitching a ride? I don’t think so! There’s got to be-”

“I think he’s right Dean.”

Apparently Sam’s come out of his stupor. Although with the junk he’s spewing, Dean’d almost have preferred he stay mute. “Not you too Sam.”

“Look, after what Zachariah almost got away with the last time we ran into him, we need to start thinking about insurance policies.” Sam’s got his sincere, pedal-to-the-metal face on, the same one he wore when he was talking about drinking demon blood for the greater good or getting Dean to kill him off before he went dark side. So yeah. Not the best memories of that face. “If either side gets a hold of us, they’re gonna torture us until we give in. It’s already almost happened twice, and I know I’m not gonna be able to just sit there while someone flays your insides. So. We need a back-up. If we have to say yes. Something that’ll keep them out regardless.”

That makes a creepy amount of sense. Shit like that is the reason that Sam should’ve been a lawyer. When fucking your brother suddenly sounds like a good idea, you know someone’s messed with your head. “Yeah, and I get that man, but you do realize what that means, right? Having sex with each other. Like, bi-weekly. And not being able to go have a quickie afterwards to shake it off.”

Sam tries a weak attempt at a smile. “Hey, you keep saying I should get laid, right?”

“Yeah, but not by me, dude!” Dean runs his hands through his hair. Of all the days for the world to get even more insane. And he’d thought the fucking apocalypse was bad enough. “I mean, how would we even...” The words get clogged up in his throat, ‘cause shit, he really does not want to be thinking about this. “No offense Sam, but you don’t really get me going. One of us is gonna need to be feeling something for this to work, and somehow I don’t think that’s happening.”

“Uh, I’m gonna head to the kitchen.” Bobby tries to make a quick escape, but Dean jams his leg in front of the chair. 

“Nuh-uh. You think we should do this, then you get to hear all the dirty details.” Crossing his arms, Dean stares down his brother. “Face it Sammy. This is not an option.”

Sam mimics his posture with a blatantly fake smirk. “There’s pills for that sort of stuff if you can’t get it up, old man.” When Dean just growls at him, he drops the posturing, suddenly looking very young and sad and worn out. And he’s got to know what that does to Dean, because Dean’s suddenly feeling like he needs to tuck his little brother away from the world. Protect Sammy’s always been his motto, and nothing reminds him of it more than that damn face. “Dean, please. This is bigger than us. Besides, if we say we won’t let it get between us, it won’t.” He pauses, then tries to smile again, looking very much like a battered puppy still trying to please. “I mean, it’s just sex, right?”

Just a couple of words from Sam and that fucking look and all the fight goes out of Dean. His shoulders slump in as he sighs. “Just sex. Right.”

They’re so screwed.

*****

So, guess what? It’s pretty damn awkward. 

They get the hell out of Bobby’s house, because there’s no way they’re going to pollute their memories of childhood with fraternal butt-sex. Some things are sacred. Besides, having someone else around that knew what was going on? Definitely gonna kill any kind of arousal Dean could drum up.

And he was gonna need to be hard. ‘Cause was gonna need to stick it to his brother. Or, at least, he assumed he was the one that needed to be hard. Of course, Sam probably assumed he was going to top. But there was no way that was happening. He was not about to let his monster sized little brother with his probably-proportional dick anywhere near his ass. Right? Right.

He parks the car sharply outside a crappy little motel twenty miles down the road from Bobby’s. Neither of them bother getting out.

Dean clears his throat. “Uh, Sam. Do you wanna go get us a room?”

“What’re you gonna do?”

Rubbing the back of his neck nervously, Dean thinks ‘doing it for Sammy’. “I’ve gotta go get some, uh, stuff. So.”

Judging by how fast he blanches, Sam got it. “Right. Yeah. I’ll, room. Yeah.” He nearly knocks his giant head on the car as he struggles to get himself out of the car as fast as humanly possible. He looks like an oversized broom trying to escape a hamster-ball. 

Not that the Impala looks anything like a hamster ball. Dean pets her wheel soothingly, then eases her into reverse and goes off on his expedition.

He stumbles into the motel room a few hours later severely traumatized. 

And here he’d thought sex shops were fun.

Sam’s on his laptop, gnawing at his nails like he hasn’t since he was ten. Instinctively, Dean delivers a harsh rap to the back of his hand. “Hey. Cut it out.”

“Right.” It’s almost like Sam had no idea what he was doing. He blushes and slams his laptop shut. His hair is slightly damp, like he took a shower a while ago. “You wanna give me the, uh, stuff and go get cleaned up?”

Oh great. Pre-sex showers that they were going to pretend weren’t pre-sex showers. This was fun. He shoves the stuff at Sam and hopes the items freak him out as much as they did Dean, before storming into the bathroom. He grins at his reflection in the mirror when he hears a grunt of disgust from the bedroom.

Since apparently Sam’s decided to forgo the sappy feelings talk before they get to fucking around with each other, thank god, Dean figures he might as well get warmed up for the main event. Obviously, he won’t be able to keep it up all the way once he saw Sam, but if he’s already horny, it’d probably make the whole thing bucket-loads easier.

He reaches down to grab his dick in one hand, caressing it smoothly. He isn’t one for hard and fast, really. Or, he is, as much as any guy was, but he likes the finesse of sex. Taking his time, getting all he can out of it. And he’s damn good at it too. Never had any complaints, but definitely had quite a few satisfied customers. His grin stretches wider at that, and he leans his head back, eyes fluttering closed as he thinks of the little brunette back in Wisconsin. She’d been real enthusiastic, all sorts of babbled exclamations, her tits heaving with each breath. Mmmm, or pretty little redhead from last year. He’d liked her enough to go home with her for a couple more rounds. She’d had long, long legs and knew just how to wrap them around him just right...

‘Course, Sam has long ass legs too, but they won’t be doing any wrapping around. This shit needs to be impersonal, or they’d never manage it without fucking things up. So, probably... Doggystyle. Ugh. He doesn’t even want to think about his little brother getting on his hands and knees for anyone, let alone him. Dean shakes his head to clear it, and realizes his erection’s already fading, thinking about Sam. He shuts off the water and dries off hurriedly before it can wilt completely.

Wrapping himself in the shabby towel, he enters the bedroom to find Sam laying on his bed, shirt already off, sweatpants on, and condoms and lube arranged on the side table. He sits up as soon as Dean enters and doesn’t seem surprised to see him half-hard. “So. How’re we going to do this?”

That business-like tone makes it a hell of a lot easier for Dean. This is just another job, something they’ve got to do to stop the apocalypse. He runs a hand thorough his hair and moves to sit beside Sam. “I figure we should take turns as far as, you know.”

Sam nods hurriedly. “Yeah. That’s good.” There’s a pause and then he admits. “I did some research.”

“I figured.” Reaches over to the bag he’d stashed away from Sam. “I got a book.” He hands over the trashy paperback, trying not to look at it. “I figure... we’ve got to do this and we can’t be with anyone else... So if we’re gonna be stuck like this, might as well try to make it good.

“Yeah.” Sam’s feet bounce anxiously across the floor. “Look, I... I figured you’d want to, um, go first. So. I got... I figured it’d be more efficient if I got myself ready beforehand.”

Startled, Dean glances at the lube, and sure enough, it’s been opened. There’s obviously been some used. “Oh.” He swallows at the thought of Sam lubing himself up with Dean in mind. There’s a strange... allure to that. “Efficient. Right. Good idea Sam.”

“Thanks.” There’s another drawn out pause and Sam sighs. “Do you want to get this over with?”

Thankful that they’re just gonna do it, Dean jumps to his feet. “Yeah. Yeah sure.” He glances down at his cock. It’s barely hard at all now. “Why you, um, get comfortable and I’ll get warmed up?”

Sam looks on the verge of making a bitchy comment, but he bites it back and shoves his sweats down. He’s not wearing anything underneath. Make that definitely proportional. Switching doesn’t sound so good anymore. And shit, what if he’s a grower?

He averts his eyes to gaze down at his own dick, which is a decent size as well, if he does say so himself. Pulling on a condom, he can’t help peaking up to see Sam arranging himself on the bed. He swallows. “Look, I’ve... I’ve never done this before. With a guy or anything.”

“Me neither.” Sam’s head hangs forward as he positions himself on his hands and knees. He looks back at Dean with a shaky smile. “Don’t worry. I’m not expecting the gay sex guru.”

The words sting, even though there’s no reason they should. He climbs up on the bed behind his brother. “Well.” His hands settle on Sam’s hips naturally, as if Sammy were just another girl, albeit a kinky one. He hasn’t been with a girl into anal, but he does this position and things can be that different, right? Just... different hole. He tugs Sam’s ass up slightly until he can see his entrance. It’s smeared with the clear glimmer of lube and twitches under his gaze. Flutters, like it’s inviting him. Intrigued, he rubs against the edge and Sam gives a full body shudder that catches him by surprise. He does it again, for the same reaction and isn’t disappointed.

“Dean,” Sam breathes and a glowing warmth settles low in his body.

Not really thinking it through, he flips Sam over easily, taking advantage of Sam’s surprise to pull his legs up around his waist and dip down to rub his cock against the crack of Sam’s ass. “Need to see your face,” he mutters in explanation, before pushing forward slightly so the head of his dick is pushing at the small indentation.

“Thought you’d be imagining a girl,” Sam replies breathlessly, tightening his legs around him while wrapping his arms around his neck. There’s a surprising intimacy to it, all of Sam clinging to him, as if Sam needs him. He hasn’t felt like Sam really needed him since he was seventeen. The feeling makes him take a deep breath in and plunge downwards to meet Sam’s lips as he pushes in.

He can’t get over the fact that it’s Sam’s mouth he’s kissing, Sam’s body that he’s thrusting into. Sam that’s making loud, wet panting noises into his mouth, too startled by sensation to kiss properly. It’s all wet with tongue and salvia and Dean can’t get enough of it, gripping the side of Sam’s face with one hand and his hip with the other.

When he’s finally fully seated within his brother, he pulls back, gazing awestruck into Sam’s equally wide eyes. “Sam,” he gasps out, tracing his features as if he’s never seen them before. “Sam,” and it’s a prayer, a pledge and everything in between as he pulls out slowly and rocks back in.

They’ve always worked well together, always been physically in tune. He doesn’t know why he thought this would be different. It’s a fluid wave of motion as he thrusts in and out, Sam’s hips always raising in time to meet him while his mouth does the same. Dean kisses any part of Sam he can reach easily, lingering at his neck, sucking on the skin as if it will disappear at any moment. 

“Dean!” Sam calls out and hugs him closer as their tongues tangle without reserve. They grind slowly for a while, just feeling each other touching everywhere and Dean realizes no one else has ever had Sam like this. No one else has seen him like this, all sweet and pliant and desperate. This is Dean’s, one more piece of Sam he can tuck away all for himself. 

And Dean- he’s never had sex like this. Never felt this much, never felt this good. Sam’s body is hot and tight and clinging, embracing him wherever he reaches. Accepting him without a thought. Only him. He grunts and mouthes at Sam’s neck as he reaches his climax and comes.

It takes him a few seconds to come down from his high enough to reach between them to give Sam a couple sloppy jerks to his cock. It doesn’t take long for Sam to reach the edge, arching back and tightening around Dean’s nearly soft dick in a way that barely distinguishes between pain and pleasure.

They both lay there for some time, panting into each other’s skin. Dean has the presence of mind to pull out a minute or two in, both of them wincing at the feeling. He flops down on his back next to Sam and tries not to remember exactly how good his brother was at taking in him in every single way.

Oh yeah, they’re definitely screwed.

*****

It becomes easier -and harder- over the next couple of weeks.

It’s easier because they keep having amazing sex. It’s harder because they keep having amazing sex.

Logically he knows that sex with Sam should not be the best sex of his life. Especially considering neither of them are gay. But he can’t deny it, can’t call it a fluke. Every time they climb into bed together, it’s fireworks and unicorns and every other cheesy, gay cliche he can come up with. Dean’s pretty sure the sex he has with his brother is the kind chick porn novels are written about and isn’t that every kind of disturbing?

And then there’s all the other stuff too. There’s this new kind of intimacy to their relationship. Dean had expected things to get awkward because, yeah, sex changes things. But it doesn’t. 

Instead, it gets good. Like, really good. Like, he and Sam haven’t been this connected ever. And considering the amount of codependency they had going on before, it’s kind of crazy to know there’s this whole other level too. They’re all comfortable with each other, dialogue flowing between them with ease. They’ve always been highly aware of each other, but it’s ramped up like crazy, until Dean’s pretty sure he could tell you how Sam was feeling by the twitch of one eyebrow.

And surprisingly, most of the time that feeling is good. Despite the apocalypse, despite the demons and the angels and fuck knows what else, Sam’s laughing more than he has in years. Over a decade, even.

Dean feels better than he has in ages.

And then he remembers he’s fucking his kid brother. That’s kind of a downside.

He can tell when it hits Sam too. When Sam reaches over to touch him and then pulls back, a frown on his face and doubt twisting his forehead as he stares sidelong at Dean. 

They don’t talk about it. The good, the bad, or the sex. The only time any of it comes up is when they climb into bed together every third day. Even then, it isn’t much. Whoever’s topping gets to decide the position, what they do. They’ve been experimenting for months, trying out anything and everything. They’ve done kinks and vanilla. They’ve tried shower sex, and car sex on one memorable occasion. Turns out it’s a little hard to fit two men over six feet into the back of the Impala. But they’d managed, even if Sam had bitched all of the next day about back pains.

The most they say during the actual sex is litanies of each other’s names and choice curse words. They don’t talk. Dean’s fine with that, because he’s never been big on dirty talk in the first place and Sam’s little sex noises are just that much better. 

They’re both pretty noisy actually. He tries not to wonder if it’s a genetic thing.

He hates that he’s having sex with his kid brother. But he can’t deny that it’s just about one of the best things that’s ever happened to him in his life.

Sam’s got him in his lap today, his back to Sam’s chest as Sam shoves him up and down with ease, as if he’s a rag-doll. Dean’s moaning and thrashing about, biting at Sam’s jawline when it’s in reach, feeling his neck being sucked on when it’s not. “Dean,” Sam mumbles in a rush of hot air against the nape of his neck, then bites down. He cries out, grabbing at Sam’s hair to pull him even closer, striping his own cock with his other hand. He loves the way Sam does this, just envelopes him with his body, regardless of who’s fucking who. He clings to it.

“God, Sam!” He grabs at his brother, pulling any part of him he can find closer. He needs him, the smell of him in his nostrils, the feel of him under his palms. “Sam, oh-oh-oooooh!”

He comes as Sam presses a light kiss to the back of his neck and whispers, “Mine.”

And that might be just about the most frightening thing of all.  
*****

It doesn’t take long for the armies of heaven and hell to figure out what they’re up to. Apparently, they can smell it on them. Or, at least, that’s what Zachariah says when he catches up with them in Jersey.

He sneers, old face twisted up in disgust and loathing. “If there anything you mud-monkeys won’t do? You claim to be good, and yet, here you are, celebrating in the filth of your own sordid relationship!”

Dean doesn’t really have any retort for that. A gag pretty much ensures that. He glares daggers at the angel while working fiercely at unknotting the ties behind him. Zachariah doesn’t get the memo, thank god, and keeps monologuing. “I mean, really. We all knew you two had your issues, and plenty of them, but I would’ve hoped you’d know better than this.”

He manages to work the gag out of his mouth and spits, “Well, you feathered fucks didn’t exactly leave us any other options.”

“Oh please,” Zachariah waves a dismissive hand. “Don’t pretend you are doing this for anyone other than yourselves at this point. I can practically taste your pathetic need for each other. No, you grabbed the first excuse you got and you ran with it.” Zachariah turns his eyes to meet Dean’s, and they really are quite evil for someone supposed to be an angel. “What would your father say?”

There’s a bang as Sam manages to get free of his bonds and goes for Zachariah.

A hemorrhaging stomach, three crony angels, and an intervention by Castiel later and they’re safely on the road again, with Cas back to who knows where. Dean is stiff and tense as he drives, determinedly not looking over at the left side of the car.

“Dean.” Sam’s fingers land on his shoulder and he shrugs them off. “Dean,” he repeats, and tugs at his sleeve. “Dean, we need to talk.”

“Fuck off Sam, kinda busy here. I can’t deal with whatever you’ve decided you need to chat about now. Amazingly, I’ve got more important things than you on my mind,” he bites out. It’s the first time he’s been really vicious since they... Well.

Sam pulls back, stunned and curls up on his side of the car. Dean refuses to feel guilty. There are more important things to deal with than the pseudo-relationship that they’d somehow dreamed up. He didn’t know why he hadn’t seen it, but he was going to put a stop to that shit. They were fucking because they had to, they need to remember that. Enjoying it was nice, but not necessary. Obviously, they’d gotten confused, what with the whole thing being monogamous. Their dad (and he winces at the thought) had raised them right, after all, told them how to treat a girl you were committed to. That’d been all whatever this was. Ingrained training.

Rain is pounding down on the car. It’s so fucking appropriate he can’t breathe.

“Pull over,” Sam says, voice tight.

“No.”

“Pull. Over.” There’s no mistaking the thread of command running through Sam’s voice, or the threat contained within.

Dean pulls the car over. 

They both sit, staring out at the rain. Then Sam says, in a voice so small it’s nearly inaudible, “I can’t lose you again Dean. Not after we just found each other.”

It’s cheesy, sappy, and sentimental. It reminds Dean of sitting in a hospital bed hearing Sam tell him he couldn’t die because they were just becoming brothers again. He turns his head to stare out the driver’s side window. Reaches over to rest his hand on Sam’s thigh. “I’m not going anywhere.”


End file.
